• Clean Technology
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• v.28 no.1
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• pp.9-17
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• 2022

Electrochemical carbon dioxide (CO₂) reduction technology, one of the promising solutions for climate change, can convert CO₂, a representative greenhouse gas (GHG), into valuable base chemicals using electric energy. In particular, carbon monoxide (CO), among various candidate products, is attracting much attention from both academia and industry because of its high Faraday efficiency, promising economic feasibility, and relatively large market size. Although numerous previous studies have recently analyzed the GHG reduction potential of this technology, the assumptions made and inventory data used are neither consistent nor transparent. In this study, a comparative life cycle assessment was carried out to analyze the potential for reducing GHG emissions in the electrochemical CO production process in a more transparent way. By defining three different system boundaries, the global warming impact was compared with that of a fossil fuel-based CO production process. The results confirmed that the emission factor of electric energy supplied to CO₂-electrolyzers should be much lower than that of the current national power generation sector in order to mitigate GHG emissions by replacing conventional CO production with electrochemical CO production. Also, it is important to disclose transparently inventory data of the conventional CO production process for a more reliable analysis of GHG reduction potential.

• Journal of Biomedical Engineering Research
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• v.42 no.6
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• pp.259-267
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• 2021

Recently, the market for personal health care and medical devices based on Bluetooth Low Energy(BLE) has grown rapidly. BLE is being used in various medical data communication devices based on low power consumption and universal compatibility. However, since data errors occurring in the transmission of medical data can lead to medical accidents, it is necessary to analyze the causes of errors and study methods to reduce data error. In this paper, the minimum communication speed to be used in medical devices was set to at least 800 byte/sec based on the wireless electrocardiography regulations of the Ministry of Food and Drug Safety. And the data loss rate was tested when data was transmitted at a speed higher than 800 byte/sec. The factors that cause communication data error were classified, and the relationship between each factor and the data error rate was analyzed through experiments. When there were two or more activated peripherals connected to the central, data error occurred due to channel hopping and bottleneck, and the data error rate increased in proportion to the communication distance and the number of activated peripherals. Through this experiment, when the BLE is used in a medical device that intermittently transmits biosignal data, the risk of a medical accident is predicted to be low if the number of peripherals is 3 or less. But, it was determined that BLE would not be suitable for the development of a biosignal measuring device that must be continuously transmitted in real time, such as an electrocardiogram.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.453-466
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• 2022

This study attempted to examine the role of gender roles in psychological distress of Korean adult men. Specifically, it was attempted to verify whether compliance with multidimensional male gender roles predicts psychological distress through gender role conflict. To this end, this study was conducted on 358 male participants aged 19 to 39 using the Korean Conformity to Masculine Norm Inventory, Korean Male Gender Role Conflict Scale, and General Health Questionnaire. As a result of the study, it was found that the influence on psychological distress through male gender role conflict was different depending on the sub-factors of the male gender norm. The sub-factors of masculine norms, 'power and control', 'job - independence', and 'emotion suppression', were statically predicted psychological distress through the medium of 'fear for femininity', which is a sub-factor of gender role conflict. Meanwhile, among the male norms, 'male leadership' and 'family support' had negative direct effects on psychological distress, and the indirect effects through gender role conflict were not significant. The results of this study suggest that the sub-factors of male norms have different functions for psychological distress, and in particular, the dysfunctional role of male norms can be caused by negative emotions about femininity during gender role conflict.

• Journal of Korea Entertainment Industry Association
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• v.14 no.2
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• pp.51-62
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• 2020

The study was conducted to verify the causality of the ability of high school and college dance majors to influence the successful goal orientation and how the change in goal affects the sense of dance performance self-confidence. In this regard, 172 dance majors were collected to collect data on their belief in dance ability, the direction of mastery goal of approach and avoidance, and the measure of confidence in dance performance, and the results of their studies were derived through correlation and structural equation analysis and path analysis. The analysis results showed reasonable factor structure and reliability based on the preceding study of feasibility analysis results between variables. Thus, the structural equation for the study variables confirmed that the theoretical hypothesis was suitable, and the path of each variable was verified through the path analysis. The analysis showed that the increased belief that ability can be improved by effort has been found to improve the effort and consequently the confidence in dancing. Also, the fixed belief that ability is not changing in a fixed sense has been found to affect the avoidance goal and reduce confidence. It can be interpreted that the more one believes that one can change one's ability by effort, the more one strengthens one's actions to achieve one's goal, thereby improving one's dance confidence. Therefore, it is deemed necessary for subsequent studies to explore whether the paths of these models differ by their major or dance careers, and to apply variables that can measure the success or failure of actual performances to enhance the explanatory power of these research variables.

• Journal of the Korean Orthopaedic Association
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• v.56 no.3
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• pp.215-223
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• 2021

Purpose: Distal radius fractures in youth are treated conservatively in most cases, but there are some cases of redisplacement in the follow-up period after cast immobilization, even after complete reduction. This study examined the risk factors of redisplacement in reduced unstable distal radius fractures. Materials and Methods: From February 2011 to June 2018, 44 unstable distal radius fractures were managed with a closed reduction and cast immobilization. The patients were aged between 6 and 14 years. The cases of redisplacement were analyzed with the fracture characteristics (fracture obliquity, fracture level ratio, ulnar fracture combined), cast qualities (gap index, cast index, 3 point index, and radius-2nd metacarpal angle) and host factors (age, sex). Results: The mean angulation in the union was 9.2° (0°-32.8°). In the categorical grouping 29 cases were within 10° angulation, and 15 cases were more than 10°. No significant differences in the factors of the cast indices or host factors were noted. The meaningful factor was the fracture level calculated by the relative width of the fracture site divided by the sum of width of diaphysis and epiphysis (p=0.001) and combined ulnar fracture (p=0.019). Conclusion: Unstable distal radius fractures should be treated with more stubborn guidelines lest the fracture loses its anatomical alignment. In particular, in patients with less remodeling power, operative treatment would secure a better result if the fracture occurs in a more proximal location.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.19-28
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• 2022

This study aimed at public officials who are most strongly demanded to tear up the corruption and diagnosed what they really think about 'the corruption'. So, a qualitative research method called 'subjectivity study' or 'Q methodology' was used to typing on the perception of corruption. In other words, 30 Q-samples related to corruption and P-samples composed of 30 public officials were investigated to derive the analysis results. As a result of the analysis, three types of perceptions of corruption were defined. That is, showed a high distribution of civil servants such as 'educational administration' and 'teacher', and and showed a high distribution of 'general administrative positions' civil servants. Also, among the respondents of , it was found that the distribution of 'high' was higher for the level of corruption in our society, and the distribution of 'medium' for and was found in the case of the respondents with high factor weight. The overall explanatory power was high at 62.11%, and based on the series of results, a hypothesis could be found that 'the perception of corruption differs according to the characteristics of the work of public officials'. By the results, the commonly recognized terms for 'corruption' were 'politician/politician' and 'solicitation'. Therefore, based on a series of results, this study is expected to be the 'Priming' for finding ways to move toward a more transparent society by diagnosing and reflecting on the thoughts of corruption in our society once again.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.207-215
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• 2021

A forklift is an industrial vehicle with a power-operated fork for lifting and moving heavy loads over short distances. A significant number of accidents are caused by forklifts every year. Most of them are known to be caused by the unsafe acts of workers. However, only a few studies have focused on the risks of forklift work from the perspective of human error. In addition, various methods have been developed to analyze the risk of human error, while it is hard to find studies that directly compare the effectiveness or strengths/weaknesses of those methods. This study aims to analyze risk factors related to unsafe behavior in forklift operations using two representative human error analysis techniques, i.e., .SHERPA and HE-HAZOP, and compare their advantages and disadvantages. The analysis was performed on three main forklift operations ('unloading from the truck', 'moving and loading into the storage', and 'loading on the truck'). As a result, 118 errors and 34 remedial measures were derived by SHERPA. Through HAZOP, 139 errors and 54 measures were derived. The two techniques were compared in terms of the number of results and the method of deriving errors and remedial measures, cause analysis, and risk assessment. This study might be used to reduce human error related disasters in workplaces using forklifts. In order to provide a guide for choosing an appropriate analysis method, more comparative studies on different techniques involving wide range of tasks are needed in the future.

• Journal of Korea Entertainment Industry Association
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• v.14 no.2
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• pp.195-203
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• 2020

Purpose: This study was a descriptive study to investigate on the effect of calling, self-efficacy, workplace bullying on retention intention among nurses in small and medium-sized hospitals. Methods: The research subjects were 224 nurses selected through convenient sampling from among those who have worked six months or longer in seven small and medium-sized hospitals located in G City. The data were collected using a structured questionnaire from July 17 to 30, 2018. The data was analyzed by descriptive statics, a t-test, ANOVA, Scheffé test, Pearson's correlation coefficient, and a stepwise multiple regression using SPSS/WIN 22.0 program. As a measuring tool, Calling was the Calling & Vocational Questionnaire (CVQ) developed by Dik, Eldrige and Steger (2008). Self-efficacy was developed by Sherer et al. (1982) and modified by Jeong Ae-soon (2007). Workplace bullying was developed by Einarsen, Raknes and Matthiesen (1994) in the Norwegian Negative Behavioral Experience Questionnaire (NAQ), and by Nam Woong et al. (2010). The retention intention was to use NRI (Nurses' Retention Index) developed by Cowin (2002) as a tool for Kim Min-jung (2006). Results: Factors affecting nurses' retention were analyzed. The analysis showed that retention intention was positively affected by self-efficacy (β=.24, p<.001), sense of calling (β=.23, p<.001) and annual wage (β=.21, p=.001) and negatively affected by workplace bullying (β=-.16, p=.008) on a statistically significant level, with an explanatory power of 28.6%.

• The Journal of the Acoustical Society of Korea
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• v.41 no.3
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• pp.326-334
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• 2022

In this paper, we propose speech enhancement algorithm as a pre-processing for robust speech recognition in noisy environments. Auxiliary-function-based Independent Vector Analysis (AuxIVA) is performed with weighted covariance matrix using time-varying variances with scaling factor from target masks representing time-frequency contributions of target speech. The mask estimates can be obtained using Neural Network (NN) pre-trained for speech extraction or diffuseness using Coherence-to-Diffuse power Ratio (CDR) to find the direct sounds component of a target speech. In addition, outputs for omni-directional noise are closely chained by sharing the time-varying variances similarly to independent subspace analysis or IVA. The speech extraction method based on AuxIVA is also performed in Independent Low-Rank Matrix Analysis (ILRMA) framework by extending the Non-negative Matrix Factorization (NMF) for noise outputs to Non-negative Tensor Factorization (NTF) to maintain the inter-channel dependency in noise output channels. Experimental results on the CHiME-4 datasets demonstrate the effectiveness of the presented algorithms.

• Korean Journal of Materials Research
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• v.32 no.11
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• pp.481-488
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• 2022

The Cu₂ZnSn(S_xSe_1-x)₄ (CZTSSe) absorbers are promising thin film solar cells (TFSCs) materials, to replace existing Cu(In,Ga)Se₂ (CIGS) and CdTe photovoltaic technology. However, the best reported efficiency for a CZTSSe device, of 13.6 %, is still too low for commercial use. Recently, partially replacing the Zn²⁺ element with a Cd²⁺element has attracting attention as one of the promising strategies for improving the photovoltaic characteristics of the CZTSSe TFSCs. Cd²⁺ elements are known to improve the grain size of the CZTSSe absorber thin films and improve optoelectronic properties by suppressing potential defects, causing short-circuit current (J_sc) loss. In this study, the structural, compositional, and morphological characteristics of CZTSSe and CZCTSSe thin films were investigated using X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF), and Field-emission scanning electron microscopy (FE-SEM), respectively. The FE-SEM images revealed that the grain size improved with increasing Cd²⁺ alloying in the CZTSSe thin films. Moreover, there was a slight decrease in small grain distribution as well as voids near the CZTSSe/Mo interface after Cd²⁺ alloying. The solar cells prepared using the most promising CZTSSe absorber thin films with Cd²⁺ alloying (8 min. 30 sec.) exhibited a power conversion efficiency (PCE) of 9.33 %, J_sc of 34.0 mA/cm², and fill factor (FF) of 62.7 %, respectively.